Thread: Rust removal

I experimented with mild rust / surface corrosion removal a while back, duly informed by You Tube experts and other internet sources. Here is what I found.

1. Woolworths has cheap double strength cleaning vinegar Woolworths Double Strength White Vinegar 2l | Woolworths . Soak overnight and then wash off with Scotchbrite scouring pad or similar, or steel wool, under running water and most it comes off nicely. I got excited after a test and did some old plane blades and chisels and they came out fine. Very handy for surfaces that aren't flat.

BUT I think you then need to neutralize it with a long soak in water and bicarbonate of soda mix to deal with whatever residue is left on the metal. I didn't neutralise after washing and went on to dry the tools and then apply Lanox anti-corrosion spray, but later found it had formed a rusty looking but not rust coating which is difficult to remove. Haven't worked out what went wrong in this process, but 3 deals with it.

2. Electrolysis. Nah! Supposedly brilliant but I tried it with various battery chargers. They all produced varying levels of impressive bubbling around the anode which decreased steadily to nothing further away. 24 hours or so of this treatment didn't do much on the metal overall.

3. Went back to old school steel wool and wet and dry sandpaper with WD40 or similar and a bit of elbow grease and that turned out to be best for flat surfaces like plane blades, plane soles and chisels.

I think 1. for anything beyond faint surface corrosion or awkward shapes like drill bits and properly neutralised and 3. for the final fine finish could be the easiest.

If it's just faint surface corrosion, stick with 3.

I haven't tried it, but apparently this stuff is the absolute best way to remove rust:
CRC Evapo-Rust Super Safe Rust Remover 1L EVR1 | Sparesbox

Heavy rust: wire brush; light rust: steel wool and soapy water.

I have an old chain block I picked up second-hand. The chains were very corroded. Deep pitting on some. The main reason for wanting to get rid of the rust was because everything the chain touched left brown stains. Hands included. A very messy item. I was mindful that anything I do will remove metal which serves to weaken the thing.

My partner suggested Coke. A large family-sized bottle went into a bucket along with the chain. The Coke turned dark brown after a few days and the chain looked a little better, but not much. Web hunt. Cleaning vinegar was next. Poured a bottle of the clear liquid into a bucket and progressively watched it turn brown after a few days. I’m really not sure if it was better than the Coke.

Not happy with the results, so far. I bought a couple of different styles of wire brushes to try. Two fitted to the elec drill. The other was on an angle grinder. The softer brush worked better than the tougher one, interestingly.

It came up best with the power tools but the task took ages. I probably annoyed the hell out of the neighbours.


I also came across a couple of callipers I'd left out and they had developed some rust. I took them into the kitchen and with some soapy steel wool and warm water gave them a good going over. Scrub until the soap stops turning brown. They remain stained where the corrosion was worst, but the metal is smooth to the touch and clean.

Evaporust.

I've done extensive testing using
1) Phosphoric acid
2) Vinegar (acetic acid)
3) Citric acid
4) Tannic acid
5) Oxalic acid
6) Hydrochloric Acid
7) Evaporust, uses a chelating agent called EDTA

They all work but at different speeds and depending on concentrations used.

In terms of removing metal as well as rust, which you don't want, #6 is the worst by fR
#4, 5 and 7 do not remove and significant meal or none at all.

Cost: Evaporust is great but is the most expensive by far, then comes tannic acid, and the others you can get creative with eg lemons for citric and supermarket vinegar although it is pretty weak and hence slowish.

For me a big deal is after treatment. Vinegar and hydrochloric need to be neutralised and then washed off and immediately blown dry - if you leave them wet they rapidly re-rust. The others can be just left to dry and they are OK.

Some chemicals leave a residual colour. Oxalic leaves a strongly adhering pale yellow film - not a problem if object is to be painted. Tannic acid leaves a friable blu-black colour which looks nice but will come away on your hand. This can be coated with a binder like BLO and left to dry for an antique look finish.

Battery chargers are not the best power supplies to use for electrolysis as 12V is too high a voltage. It's better to used something like 3-6V - and a non-reactive positive electrode like a carbon rod. I've done many big objects like large vices this way as a large bath of Evaporust gets expensive.

I’ve had good results on old handsaws and planes with vinegar and bicarbsoda. Seems to bubble away for a while and I use a scour pad to clean it up to finish. Was much cheaper than some of the commercial options

Evoporust, yes it's a bit expensive, but it works. They also have a spray on gel now, for things that can't be soaked, but I don't know how well it works.

Originally Posted by Fumbler

Team,

I have several old tools and drill bits that have seen better days and want to touch them up. What does everyone recommend as the go to for rust removal.

thanks

Richard

Richard

Much depends on the tool as to which method you should use and different treatments have differing results. A vice, for example, you can probably hit with almost anything you like as the likelihood is that it will be painted after so any resulting discolouration is of no importance. It will be a balance of cost and time. If you are looking at metal planes you may wish to avoid unappealing colours on the sides and sole so most of the more aggressive chemical treatments won't suit this purpose. However, where the frogs etc are to be painted or are not visible, you could use a gel type product that will be restricted to these areas.

people are reluctant to use such things as flap wheels on angle grinders as these produce aggressive swirl marks and remove metal and their reluctance is warranted. They also are useless in reaching tight spots. However, fibre wheels on a bench grinder polish rather than grind and could be used for the sides of a hand plane as an example. While they might be used on the sole too, it should only be light and in conjunction with a flatening technique. You can find fibre wheels for angle grinders too. This is on a 100mm machine and in some instances is easier to use than bringing a tool to the restricted space of a bench grinder.

P1070411 (Medium).JPG

One thing I would add is that where chemical treatments are concerned they usually require some post neutralising treatment to avoid re-rusting as it appears to make the metal even more susceptible to rust.

Handsaws are probably the most controversial area for rust treatment. The internet is littered with methods for cleaning them up and it depends what you wish to achieve. If it is a saw for your own use it may not matter what you do within reason. However, if you have some aspirations on a saw with a little history behind it and positive identification (primarily, although not exclusively, through an etch or stamp) the recommendation is to avoid like the plague anything to do with powered mechanical grinding: This includes any type of powered sanding. Similarly chemical treatments are an absolute no-no. How do you clean saws? In short, it is manual with W & D paper and lubricant. Even then great care should be taken not to erase any etch. There is a little information here.

Just on electrolysis, while it is useful on intricate objects it does impart a grey patina to surfaces that is impossible, in my experience, to remove. This is not an issue if you are painting the item, and again some protection will be required to prevent further rusting as the metal seems even more susceptible. Also you need to use electrolysis in a very well ventilated area. When I have done it, it was outside in the open.

One advantage of the chemical treatments is that they are able to get into pitted surfaces where rubbing methods do not reach. I have not commented on Evaporust as I have not used it.

Regards
Paul

Originally Posted by 419

I experimented with mild rust / surface corrosion removal a while back, duly informed by You Tube experts and other internet sources. Here is what I found.

2. Electrolysis. Nah! Supposedly brilliant but I tried it with various battery chargers. They all produced varying levels of impressive bubbling around the anode which decreased steadily to nothing further away. 24 hours or so of this treatment didn't do much on the metal overall.

.

The secret to electrolysis is to constantly clean the anode. Once it gets coated with rust particles it stops working. I use this method all the time, but I use carbon arc gouging rods with their copper coating removed as my anodes as they are self cleaning.
Rgds,
Crocy.

Hey Errol,
if you can remove that chain and have access to a cement mixer, drop the chain in there with some water and sand and let it spin over for a few hours.

Oh, that could be noisy.

I spent hours on it with various brushes. I wish this thread had been created when I needed it. I would probably have gone for one of those ideas that Bob suggested. With a chain, it seems to beg a chemical, and a few of the suggestions did no harm to the metal. That's quite appealing. I've got my chain to the stage where what rust is left can stay there. I'm so fed up with the thing.

Though, in my search for a solution I don't recall the cement mixer trick. It would probably work too, even if the chain got caught up on the mixer's innards the sand would keep moving. One solution that seemed popular in my search was to attach the chain to the towbar of a car and go driving around on a dirt track or beach for a while. That could be nasty if it got caught up on something.

It’s a variation on a technique to derust motorcycle fuel tanks. Some guys fill them full of screws of other objects, wrap them tightly in blankets and spin it over in a cement mixer or a clothes dryer until they get scrubbed clean. I suppose you could put the chain in a sealed five gallon bucket before spinning it too.

I spent some time working in a brake reconditioning workshop. After the old linings had been removed, the brake shoes were dumped into a sandblaster. This was a huge machine that had a barrel which rotated as a cement mixer does. The hatch on the machine was closed and the thing set in motion. You could hear the shoes rattling as the barrel rotated. Presumably, blasts of grit bombarded the shoes. After about fifteen minutes the shoes would come out very pitted but clean as though they’d just been manufactured.

Hi, Once used white vinegar to clean up 2 old saw blades and a rusty but unused Forstner bit, both came out of the bath black as the ace of spades will not be using it again. Any ideas how and why that would happen. Brian.